Fracture-cavern type carbonate hydrocarbon reservoir three-dimensional geological modeling method

Abstract

The invention discloses a fracture-cavern type carbonate hydrocarbon reservoir three-dimensional geological modeling method. The method comprises a step A of modeling block division. In the step A, a fracture-cavern is first divided. Then a hydrocarbon reservoir is divided. A flow unit is further divided. A three-dimensional geological model is further set up according to the flow unit division blocks. The method also comprises a step B of modeling category classification. In the step B, at least a matrix category and a crack category are divided. Step-by-step modeling operations are further performed. The method also comprises a step C of matrix modeling phase-splitting. In the step C, the matrix is divided into a plurality of reservoir body types. Reservoir facies are further divided in line with the reservoir body types. The three-dimensional geological model of each reservoir facies is respectively established. The method further comprises a step D of fracture classification. In the step D, fractures are classified according to different dimensions. Fracture models with different dimensions are further established step by step. The method further comprises a step E of model merging. In the step E, established matrix and fracture three-dimensional geological models are merged in an equivalent way to finally set up a fracture-cavern type carbonate hydrocarbon reservoir three-dimensional geological model. The three-dimensional geological model established through the method can satisfy demands of development scheme designs, development scheme implementation, development dynamic analysis, etc.

Description

technical field [0001] The invention relates to the technical field of geological modeling methods, in particular to a three-dimensional geological modeling method for fracture-cave carbonate oil and gas reservoirs. Background technique [0002] The Ordovician carbonate oil and gas exploration and development in the Tazhong area have made significant progress in recent years, and major breakthroughs have been made in the Upper Ordovician Lianglitage Formation and the Lower Ordovician Yingshan Formation in the No. The carbonate matrix of the Yingshan Formation has low primary porosity and poor permeability, and the reservoirs are mainly dissolved pores, caves and fractures formed by weathered karst of epigenetic karst, and the porosity and permeability of pores, caves and fractures are very different. Large, the reservoir heterogeneity is extremely strong, and the distribution is extremely complex. Research on modeling methods for fractured-vuggy carbonate reservoirs is stil...

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Problems solved by technology

[0008] The main purpose of the existing 3D geological modeling methods and technologies for fractured-vuggy carbonate reservoirs represented by the above-mentioned periodicals is to establish theoretical models or conceptual models of fractured-vuggy carbonate rocks to guide early oil and gas resource exploration and evaluation. After cave-type carbonate reservoirs are developed, the 3D geological model established by the above methods cannot meet the technical requirements of well pattern deployment, development index prediction, development effect evaluation and other technical requirements of the development plan. The main shortcomings are as follows: 1. The porosity and permeability of pores, caves, and fractures are very different, and the above methods cannot effectively distinguish pores, caves, and fractures and describe their three-dimensional spatial forms; 2. The epigenetic karst reservoir is mainly on the top of the weathering crust, but is affected by factors such as fractures , the development position of large-scale karst caves and interlayer karst caves still varies greatly in the vertical direction. When dividing the broken zone at the top of the cave, the main body of the cave and the broken zone at the bottom of the cave, it is impossible to determine the development position of large-scale karst caves, and it is difficult to segment; 3. Fractures and caves There are various types of fractures in carbonate reservoirs, including large-scale fractures that can be identified by seismic, small-scale fractures that can be identified by well logging, and micro-fractures that can be identified only under a microscope. The above modeling methods and technologies have not found a reasonable solution to fracture modeling, but fractures have a great impact on development in fractured-vuggy carbonate reservoirs, and ignoring the impact of fractures cannot meet the requirements of the development plan ;4. Serious leakage or venting occurs when large-scale karst caves or fractures are encountered during drilling, and well logging is impossible. The physical parameters of this type of reservoir cannot be explained by logging. The above modeling methods and technologies have not found an effective solution to reservoir parameters. Value assignment method; 5. In fractured-cavity carbonate reservoirs, the general fluid properties vary greatly and the fluid distribution rules are complex. The above modeling methods and technologies have not found a reasonable three-dimensional fluid geological modeling method

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